Abstract Skin cancer is a growing epidemic, with almost five million US diagnoses annually, in contrast with most cancers, which are decreasing in incidence. Although largely preventable, skin cancers can be deadly, debilitating, damaging, and disfiguring. US adolescents have the lowest skin protection rates of all age groups and also engage in increased ultraviolet radiation (UV) exposure as they move into adulthood. Thus, young adults are in need of intervention to reduce their skin cancer risk. Prior interventions to increase skin protection and/or decrease UV exposure among young adults have been limited in their dissemination and longitudinal assessment, and no prior interventions targeted to this population have been internet-based besides our own. Our research team developed a web-based intervention that was found to significantly decrease UV exposure and increase skin protection behaviors among young adults in a randomized controlled trial (RCT) of nearly 1000 participants recruited from a consumer research panel. The intervention (UV4.me) is individually-tailored, interactive, and multimedia in nature, and based on the Integrative Model of Behavioral Prediction. Similar to other online trials, 73% of eligible individuals completed the baseline questionnaire, 70% who were randomized to the intervention accessed it, and 68% accessed it and completed at least one module. However, we have an opportunity to increase the engagement, implementation, and ultimately, the impact of UV4.me. We will do this by adding several key interactive features/strategies suggested by participants, our data, and supported by the literature (i.e., by creating a mobile version, adding incentives embedded in the intervention, a behavior tracking and feedback feature, peer interaction component, and ongoing news updates). This Hybrid Type 2 dissemination-effectiveness project's purpose is to implement the enhanced UV4.me2 with adults aged 18-25 years at moderate to high risk of developing skin cancer and evaluate the intervention's effectiveness in a sample recruited online through national dissemination to the general population. This project will use the RE-AIM framework to determine the reach, effectiveness, implementation, maintenance, and cost of UV4.me2. The team will recruit individuals from several general online sources (e.g., nonprofits, social media, commercial). Our team has already recruited three non-profit organizations to promote uptake of UV4.me2 and a commercial skincare company to offer incentives to encourage participation of young adults from across the US. In order to evaluate intervention effectiveness, young adults who enroll in the study will be randomized to either receive the enhanced UV4.me2, the original UV4.me, or a skin cancer e-pamphlet from the American Cancer Society. In summary, this project proposes a novel approach to address an issue of growing public health significance. The uniquely well-suited multidisciplinary and multi-institution research team is comprised of junior, mid-level, and senior investigators who have previously worked together successfully on skin cancer prevention interventions.